DESCRIPTION (Applicant's Description) For nearly 20 years researchers in the field of natural killer (NK) cell biology have met at International Natural Killer Cell Workshops. These workshops have represented the primary scientific meetings held in the field. In 1991, The Society for Natural Immunity was established to serve the interests of scientists and clinicians interested in non-adaptive immunity, and particularly those interested in basic and clinical aspects of NK cell biology. This Society has assumed responsibility for publications of Natural Immunity, which is the official journal of the Society; and these meetings are now designated as annual meetings of the Society. In this proposal, we will present a detailed outline for the Fifth Annual Meeting of the Society for Natural Immunity/Seventeenth International Natural Killer Cell Workshop to be held October 17-21, 1998 at the Airlie Center in Warrenton, Virginia. This meeting has historically served as a primary focal point for researchers in this field and has attracted the preeminent scientists and clinician scientist in the field. The upcoming meeting will consist of sessions related to: Ontogeny and Differentiation of NK and NK-like Cells; Immune regulation of and by NK cells; Human and Non-Human NK Cell Receptors; Signaling and Mechanisms of Lysis; and In Vivo Surveillance by NK Cell or Tumor Cells, Viruses and Parasites. These topics are reflective of current research activities in the field and also allow opportunities for integrating developments in other areas of non-adaptive immunity and thus foster dialog among researchers in this area. Goals of the meeting are to (1) bring together senior and junior level researchers in the field of NK cells biology, and also those related in areas of significant developments in select areas of non-adaptive immunity; and (2) determine future directions in the field.